Method for arranging a fibre strand on a spinning device of a spinning station

ABSTRACT

A method for arranging a fibre strand on a spinning device of a spinning station, wherein the spinning device is fed the fibre strand in order to produce a spun thread from the fibre strand by means of a drafting unit having a plurality of roller pairs. The roller pairs of the closed drafting unit are each operated, in a manner corresponding to the predefined drafting ratio of the fibre strand, with an introduction speed lower than the operating speed of the drafting unit, the fibre strand is subsequently introduced into the clamping region of an input roller pair of the drafting unit and the drafted fibre strand, after passing through the closed drafting unit and exiting a clamping region of an output roller part of the drafting unit, is subsequently fed to the spinning device.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a 35 U.S.C. 371 national stage filing ofInternational Application PCT/EP2020/086319, filed Dec. 16, 2020, whichclaims priority from EP National Patent Application No. 19217660.0,filed Dec. 18, 2019, entitled “Verfahren zur Anordnung eines Faserbandsan einer Spinneinrichtung einer Spinnstelle”, the entire contents ofwhich are incorporated herein by reference.

FIELD OF THE INVENTION

The present invention relates to a method for arranging a fibre strandat a spinning device of a spinning station, wherein the fibre strand isfed, by means of a drafting system having several roller pairs, to thespinning device for the manufacture of a spun thread from the fibrestrand.

BACKGROUND OF THE INVENTION

Spinning stations, at which a supplied fibre strand is drafted by meansof a drafting system and then spun into a thread by a spinning deviceand wound onto a take-up package, are known in various embodiments fromthe prior art. A plurality of spinning stations arranged next to oneanother forms a textile machine, in which threads are spunsimultaneously from supplied fibre strands.

Before the spinning process starts, it is necessary to pass the fibrestrand through the drafting system and then to arrange the drafted fibrestrand in a starting position at the spinning device, in which startingposition the fibre strand can be received by the spinning device andspun into a thread. In order to previously arrange the fibre strand atthe drafting system, it is currently necessary to open the draftingsystem, e.g. by disengaging the top rollers of the roller pairs, whichtop rollers are arranged on a weighting arm, from their associatedbottom rollers. After the drafting system is opened by swivelling of theweighting arm, it is possible to insert the fibre strand into thedrafting system in a predefined manner. This is followed by a return ofthe weighting arm to the closed position of the drafting system, inwhich closed position the drafting system is then started and the fibrestrand is drafted in a predefined manner according to the rotationalspeeds of the roller pairs, which rotational speeds differ for the draftratio to be achieved.

The necessity to open the drafting system to arrange the fibre strandresults in relatively long downtimes at the individual spinningstations, which reduces the productivity of the spinning station. Inaddition, the need to open the drafting system requires an appropriatemechanical design that ensures reliable opening and closing movement.

Proceeding therefrom, the problem addressed by the present invention isone of providing a method for operating a spinning station that enablessimple and efficient arrangement of the drafted fibre strand at thespinning device.

SUMMARY OF THE INVENTION

The present invention solves the problem by a method for arranging afibre strand at a spinning device of a spinning station, wherein thefibre strand (3) is fed, by means of a drafting system (1) havingseveral roller pairs (5, 5 a, 6, 6 a, 7, 7 a, 8, 8 a), to the spinningdevice (2) for the manufacture of a spun thread from the fibre strand(3), characterised in that: the roller pairs (5, 5 a, 6, 6 a, 7, 7 a, 8,8 a) of the closed drafting system (1), which in particular areindividually drivable, are each operated, in accordance with thepredefined draft ratio of the fibre strand (3), at an insertion speedwhich is lower than the operating speed of the drafting system (1), thefibre strand (3) is then inserted into the clamping area of an inputroller pair (5, 5 a) of the drafting system (1) and the drafted fibrestrand (3) is then fed to the spinning device (7) after passing throughthe closed drafting system (1) and exiting a clamping area of an outputroller pair (8, 8 a) of the drafting system (1).

Advantageous further developments of the present invention are statedherein.

The method according to the present invention is characterised in thatthe roller pairs of the closed drafting system, which in particular aredriven individually, are each operated, in accordance with thepredefined draft ratio of the fibre strand, at an insertion speed whichis lower than the operating speed of the drafting system, the fibrestrand is then inserted into the clamping area of an input roller pairof the drafting system and the fibre strand is then fed to the spinningdevice after passing through the closed drafting system and exiting theclamping area of an output roller pair of the drafting system.

According to the method according to the present invention, opening ofthe drafting system, in the case of which opening, for example, the toprollers of the roller pairs of the drafting system are lifted off therespective bottom rollers, is not required as it is in the methods knownfrom the prior art. In the method according to the present invention,the fibre strand is inserted into the drafting system in its closedstate. For this purpose, the stationary roller pairs of the closeddrafting system are first set to an insertion speed that issignificantly lower than the operating speed of the roller pairs duringthe regular spinning process. The possibility of having the roller pairsrunning synchronously at a low speed according to the draft ratio to beachieved for the fibre strand, in particular by means of an individualdrive technology, allows the fibre strand to be inserted manually or inan automated manner into the clamping area of the input roller pair andsubsequently to be passed through the drafting system in a controlledmanner. Even at the lower input speed, the fibre strand is drafted bymeans of the specified rotational speed difference between the rollerpairs according to the draft ratio to be achieved, the preferredindividual drive of each roller pair responsible for the draft allowingextremely reliable synchronism and consequently an exactly set draftratio to be achieved during the fibre strand feed toward the spinningdevice. Furthermore, the roller pairs can particularly preferably beoperated individually, more preferably independently of each other, bymeans of the assigned individual drives in such a way that the speed ofeach roller pair can be variably adjusted in the driven state ifnecessary, for example to be able to adjust the draft ratio in anautomated manner or manually at any time according to the requirement.According to a preferred embodiment, the bottom rollers of the rollerpairs are individually driven. According to an alternative embodiment,however, the individual drive of the top roller of a roller pair canalso be provided.

After the drafted fibre strand has exited the clamping area of theoutput roller pair, the fibre strand is fed to the spinning device insuch a way that the fibre strand can be subjected to the spinningprocess there. In the course of starting the spinning process, thedrafting system can then be operated at its operating speed again sothat the spinning process can be carried out in a predefined manner atthe spinning station.

The method according to the present invention makes it unnecessary toopen the drafting system for a relatively long time, thus interruptingthe spinning process. In addition, the fibre strand emerging from thedrafting system already has the drafting required for the subsequentspinning process, so that the spinning process can be startedimmediately with the fibre strand emerging from the drafting system. Thepossibility of operating the drafting system at an insertion speed lowerthan the operating speed allows the fibre strand to be aligned exactlywith the drafting system in a special manner. The arrangement in theclamping area can, for example, be carried out by the operatingpersonnel, who also monitor the guidance of the fibre strand through thedrafting system and the arrangement at the spinning device. The lowinsertion speed allows very accurate monitoring of the process ofinsertion into the drafting system and forwarding to the spinningdevice.

The method according to the present invention can in principle beapplied to any spinning stations having drafting systems. For example,it is possible to carry out the method on a spinning device having aring spinning apparatus. According to a particularly advantageousembodiment of the present invention, however, the fibre strand, afterpassing through the drafting system, is fed to a spinning devicedesigned as an air-jet spinning device. In the air-jet spinning deviceof the spinning station, the outer free fibre ends are spirally woundaround the core fibres, by means of a compressed air flow generated by anozzle device, to form the thread. The free end of the fibre strandlying in front of the air-jet spinning device is sucked into the air-jetspinning device by a suction air flow.

The use of the method according to the present invention in connectionwith an air-jet spinning device, which use is advantageously provided,is thus characterised in that the spinning process can be startedwithout any significant delays after the drafting system has been passedthrough, whereby the effectiveness of the spinning station isadditionally increased.

According to a further embodiment of the method, a suction air flowgenerating device is activated to generate a suction air flow in thearea of the air-jet spinning device before or during the arrangement ofthe fibre strand at the air-jet spinning device. According to aparticularly preferred embodiment of the present invention, a compressedair source, which normally interacts with the air-jet spinning device,and more preferably also a vacuum source are activated as the suctionair flow generating device even before or during the arrangement of thefibre strand at the drafting system, so that the fibre strandsubsequently fed from the drafting system to the air-jet spinning deviceis subjected to a suction air flow, which is used to insert the fibrestrand into the air-jet spinning device and/or to remove loose fibrematerial from the area of the air-jet spinning device. The suction airflow generating device ensures in a particularly reliable way that theloose fibre material does not cause blockage of the inlet or entry areaas well as the spinning nozzles of the air-jet spinning device. The airspinning process can thus be started without any problems, in aparticularly reliable way.

This further development of the present invention consequently makes useof the circumstance that known air-jet spinning devices usually alreadyhave corresponding suction air flow generating devices, which, in thecontext of the further development of the method, are activated at theappropriate time according to the process of inserting the fibre strandinto the drafting system, so that loose fibre material that is presentis reliably removed by suction. Alternatively or additionally, suctionair flow generating devices other than those mentioned above can beprovided for generating a suction air flow in the area of the air-jetspinning device. What matters most is that fibre remains in the area ofthe air-jet spinning device can be removed and/or the fibre strandemerging from the drafting system can be fed to the air-jet spinningdevice in a suitable manner.

According to a further embodiment of the present invention, it is alsoprovided that the air-jet spinning device is opened before or during thearrangement of the fibre strand at the air-jet spinning device. Knownair-jet spinning devices usually have at least two components. The firstis a nozzle device with nozzles connected to a compressed air source viaa line, the air that flows out of the nozzles serving to generate therotational flow by means of which the drafted fibre strand is actedupon. The second component of the air-jet spinning device has athread-forming element, e.g. a hollow spinning cone, which incooperation with the nozzle device forms the thread, which is drawn offfrom the spinning device through the hollow spinning cone. Opening theair-jet spinning device, in conjunction with the advantageously providedactivation of the suction air flow generating device, particularlyreliably guarantees, for example, that loose fibre material does notaccumulate in the area of the spinning nozzle and does not lead to amalfunction in the spinning process, but instead that it is removed bymeans of the suction air flow generating device. This embodiment of thepresent invention thus ensures, in a supplementary manner, that thespinning process can be started and carried out without problems afterthe arrangement of the drafted fibre strand.

According to a further embodiment of the present invention, it is alsoprovided that, after the fibre strand has been transferred to theair-jet spinning device, the drafting system is stopped, the air-jetspinning device is closed and the suction air flow generating device isdeactivated. The feeding process can be interrupted manually by theoperating personnel or in an automated manner. For this purpose, forexample, a fibre strand length or a time interval can be defined, afterwhich the drafting system is automatically stopped.

This embodiment of the present invention provides for the insertionprocess by means of the drafting system to be stopped after the fibrestrand has been arranged in the entry area of the air-jet spinningdevice. After a subsequent, advantageously provided suctioning, possiblyin connection with opening of the air-jet spinning device which is alsoprovided, contamination by loose fibre material can then be removed andsubsequently the air-jet spinning device can be adjusted to its positionrequired for the spinning process. The spinning process can then bestarted, malfunctions being avoided particularly effectively.

BRIEF DESCRIPTION OF THE DRAWINGS

An embodiment example of the present invention is explained below withreference to the drawings.

In the drawings:

FIG. 1 shows a flowchart of a method for arranging a fibre strand at aspinning device of a spinning station;

FIG. 2 shows a schematic representation of an air-jet spinning devicewith an upstream drafting system and

FIG. 3 shows a schematic representation of the air-jet spinning devicein FIG. 2 in the open state.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 shows a method sequence for arranging a fibre strand 3 via adrafting system 1 at an air-jet spinning device 2 of a spinning station(not shown here), with reference to FIGS. 2 and 3 , in which thearrangement of the drafting system 1 and the air-jet spinning device 2of the spinning station is shown schematically in two positions.

To provide a drafted fibre strand 3 at an inlet of the air-jet spinningdevice 2, the individually drivable roller pairs 5, 5 a, 6, 6 a, 7, 7 a,8, 8 a of the drafting system 1 are operated in the closed state at aninsertion speed which is significantly below the operating speed of thedrafting system 1. At the same time, a compressed air source 13connected to a spinning nozzle unit 10 via a line 12 is activated togenerate a suction air flow in the area of the inlet of air-jet spinningdevice 2, and the air-jet spinning device 2 is moved from its closedposition shown in FIG. 2 to its open position shown in FIG. 3 , in whicha spinning cone unit 15 is displaced relative to a nozzle device 4 incomparison with the operating position shown in FIG. 2 .

After the activation of the individually drivable roller pairs 5, 5 a,6, 6 a, 7, 7 a, 8, 8 a of the drafting system 1 and the provision ofcompressed air by means of the compressed air source 13 in the openstate of the air-jet spinning device 2, the fibre strand 3 is insertedmanually by the operating personnel into the clamping area of the inputrollers 5, 5 a. From there, after passing through the drafting systemrollers 6, 6 a, 7, 7 a, the fibre strand 3 is transferred, at aconsiderably reduced speed in comparison with the regular operation ofthe spinning station, to the output rollers 8, 8 a, at which the draftedfibre strand 3 emerges from the drafting system 1. The insertion speedof the drafting system rollers 5, 5 a, 6, 6 a, 7, 7 a, 8, 8 a is definedaccording to the drafting of the fibre strand 3 to be achieved, so thatthe fibre strand 3 emerges from the drafting system 1 in accordance withthe specified draft ratio. Because of the alignment of the nozzles 10,11 assigned to the spinning nozzle unit 9 in a direction leading awayfrom the inlet of the air-jet spinning device 2 or in a directionleading toward the spinning cone 16, the activated compressed airgenerates a suction air flow in the area of the inlet of the air-jetspinning device 2, by means of which suction air flow the fibre strand 3emerging from the drafting system 1 can be reliably fed to the air-jetspinning device 2. The suction air flow can preferably be supported byswitching on the vacuum source 19 as required. Switching on the vacuumsource 19 also promotes the removal of fibre remains from the area ofthe air-jet spinning device 2, in particular from the area of thespinning cone 16. Via the output roller pair 8, 8 a, the drafted fibrestrand 3 is guided as required into the inlet of the air-jet spinningdevice 2 by means of the suction air flow that is present. After adefined position of the free end 24 of the fibre strand 3 within theair-jet spinning device 2 has been achieved, the drafting system 1 isstopped and the compressed air source 13 and, if switched on, also thevacuum source 19 are deactivated. Then the air-jet spinning device 2 ismoved from its open position shown in FIG. 3 to the operating positionshown in FIG. 2 .

The compressed air source 13 activated during the arrangement of thefree end 24 of the fibre strand 3 in the area of the air-jet spinningdevice 2 and optionally the switched-on vacuum source 19 ensure, amongother things, that loose fibre materials are reliably removed from thearea of the air-jet spinning device 2 and thus cannot lead tomalfunctions in the operation of the air-jet spinning device 2. Afterthe air-jet spinning device 2 has been closed, the spinning process canbe started by continuing the fibre strand feed and applying a spinningpressure by means of the spinning nozzle unit 9 and its associatednozzles 10, 11.

LIST OF REFERENCE SIGNS

-   1 Drafting system-   2 Air-jet spinning device-   3 Fibre strand-   4 Nozzle device-   5, 5 a Input rollers-   6, 6 a Drafting system rollers-   7, 7 a Drafting system rollers-   8, 8 a Output rollers-   9 Spinning nozzle unit-   10 Nozzles-   11 Nozzles-   12 Line-   13 Compressed air source-   15 Spinning cone unit-   16 Spinning cone-   17 Vortex chamber-   18 Line-   19 Vacuum source-   24 Free end of the fibre strand

1. A method for arranging a fibre strand at a spinning device of aspinning station, wherein the fibre strand is fed, by a drafting systemhaving several roller pairs, to the spinning device for the manufactureof a spun thread from the fibre strand, characterised in that the rollerpairs of the closed drafting system, are each operated, in accordancewith the predefined draft ratio of the fibre strand, at an insertionspeed which is lower than the operating speed of the drafting system,the fibre strand is then inserted into the clamping area of an inputroller pair of the drafting system and the drafted fibre strand is thenfed to the spinning device after passing through the closed draftingsystem and exiting a clamping area of an output roller pair of thedrafting system.
 2. The method according to claim 1, characterised inthat the fibre strand, after passing through the drafting system, is fedto a spinning device designed as an air-jet spinning device.
 3. Themethod according to claim 1, characterised in that a suction air flowgenerating device of the air-jet spinning device is activated before orduring the arrangement of the fibre strand at the air-jet spinningdevice.
 4. The method according to claim 1, characterised in that theair-jet spinning device is opened before or during the arrangement ofthe fibre strand at the air-jet spinning device.
 5. The method accordingto claim 4, characterised in that, after the fibre strand has beentransferred to the air-jet spinning device, the drafting system isstopped, the air-jet spinning device is closed and the suction air flowgenerating device is deactivated.
 6. The method according to claim 1,wherein the roller pairs are individually drivable.